Lapping device



R. R. SEARLES LAPPING DEVICE Dec. 27, 1938.

Filed Aug. e, 1957 llfirlh lNvENToR RAYA/MND 1Q. 554/?55 TToRNEYs.

Patented Dec. 27, 1938 My invention r device, but which honing,polishing,

' LArrlNG DEVICE Raymond R. Searles,

or to The Fafnir Bearing Company,

a corporation of Connecticut' ain, Conn.,

New Britain, Conn., assign- New Brit- Application August s, 1937, semiNo. 157,648

2 Claims.

elates to what I term a lapping may be adaptedV for grinding, etc., allof which operations I wish to include within the term lapping It is theprincipal object of my invention to provide an improved lapping device,particularly though not exclusively adapted for lapping the racewaygrooves for ball It is a further object lapping device which may be veryreadily actuated.

bearings. to provide an improved A further object is to provide animproved may be veryreadily and Another object come apparent to thoselapping device so arranged and operated that it quickly brought into andout of lappingl position.

is to provide an improved lapping device in which the lapping pressuremay be quite readily predetermined and maintained.

Other objects and various features of invention will be hereinafterpointed out or will beskilled in the art.

In the drawing which shows, for illustrative purposes only,

preferred forms of the inventionin partial section of a Fig.2 is afragmentary view, similar to Fig. 1,

and illustrating a slightly modied form of the invention.

In the particular embodiment of the invention herein illustrated forlapping the raceway grooves of ball bearings, I employ what may betermed a lapping head 5 carried by and bodily rotatable with a spindle 6rotatably mountedin ball bearuch as 1 carried by a frame 8. The lapping-ings s head 5 carries mova ble lapping tools 9 9, which in the formillustrated are pivotally mounted as at I to the lapping head so thatthe laps proper I I-I I may be moved into and out of engagement with thework which, as illustrated, is an outer ring I2 of a ball bearing. Thering I2 is carried in a suitable pocket chuck I3 on a rotatable spindleIB. The lapping tools are movable pref` erably by iiuid pressure leastone direction. As

actuated means in at illustrated, the spindle 6 is hollow and carries anactuator or draw rod I5. Adjustably mounted on the front end of the drawrod I is a toggle head I6 and toggle links I'I-I1 are pivotallyconnected to the toggle head and the lapping tools 9-9 so that when theactuator I5 and toggle head I6 are moved toward the right the laps mentwith the wor head IB and actuator left, the laps II-II will II-II willbe urged into engagek and, conversely, when the I5 are moved toward thebe moved substantially or passage members radially away from the work soas to permit the chuck to be Withdrawn and a new work piece substituted.

The actuator I5 in the preferred form is operated by huid pressureactuated means, which 5 may include a piston I8 carried by the rear endof the actuator rod I5 and mounted in a cylinder I9, as will beunderstood. Fluid pressure passages -2I communicate with the cylinder atopposite ends of the piston I8 and uid pres- 10 sure passage members orpipes 22-23 communicate respectively with the passages 20--2I and. serveto conduct pressure iluid to and from the ends of the cylinder, as willbe clear. The pipes 22-23 may be connected '5 to an ordinarythree-wayvalve, entirely familiar to those skilled in the art, wherebyiluid may be directed at will to the cylinder at one side of the pistonI8 and exhausted from the other side so as to actuate the actuator rodI5 and thus rock 20 the toggle for actuating thelappingtools 9 9.

In that form of the invention shown in Fig. 2, the parts may besubstantially the same as those shown in Fig. 1. However, the lappingtools 9'9' are provided with bulges or other means to 25 providegreaterweight, since Ain the form shown in Fig. 2 the tools 99' are adapted tobe thrown outwardly centrifugally` so as to bring the laps II-II intoengagement with the work. The toggle head It may be the same asheretofore described and preferably the links IIL-I1' are connected totools 9'Q' by a pin and slot connection indicated generally at 2i. Inthat form shown in Fig. 2, the work head spindle H is mounted on oneaxis, the center line being shown in dot-dash lines, while the spindle dis mounted upon another axis out of alignment with the axis of the workspindle IB. Therefore,

the laps II--II being generally .concentrically and symmetricallyarranged relatively tothe axis 4o IIL-the laps will engage the racewaybearing constituting the work piece at opposite sides of the groove whenthe lapping tools are arranged oppositely, all as will be clear fromFig. 2. Duringrotation of the lapping head and the work -head atdiierent speeds, the laps will traverse the raceway groove in generallyspiral fashion so. as to lap the entire surface. With the work head andthelapping head mounted on the same axis, as may be considered thecondition in Fig. 1, the laps II--II will simply track around within theraceway groove and may be considered as form laps, whereas the lapsII-II of Fig. 2 need not be form laps since the shape of the lap is notrelied of the spindle groove of the ball upon for lapping the surface,owing to the fact that the laps traverse the entire surface of the81'O0Ve.

In the form shown in Fig. 2, as stated the laps are designed to bethrown out into lapping operation and yet permit the laps to be fullyretracted bythe toggle mechanism. The laps of Fig. 1 as indicated aredesigned to be moved both into and out of engagement by means of thetoggle lever mechanism shown. By providing a yielding connection betwenthe lapping tools S- and the toggle head I6, the axes of the spindles I4and 6 could be oiset so as to cause the laps lI--H to traverse theentire groove after the manner of Fig. 2.

By means of the toggle actuation of the lapping tools very slight forceis required to move the lapping tools and the latter may be retracted topermit the insertion of a new work piece, all Without stopping therotation of the spindle 6. The fluid pressure actuated means which inthe form shown in Fig, l'serves to urge the laps into lapping engagementwith the work is highly advantageous in that there is a substantiallyconstant and uniform pressure urging the 'laps into engagement with thework and that pressure Y tends to follow up so as to cause asubstantially constant pressure on the laps even though they may Wear tosome extent. By properly proportioning and adjusting the togglemechanism as well as the uid pressure in Fig. 1, the lapping pressuremay be very accurately predetermined and maintained. By properlydesigning the lapping tools 9-9' of Fig, 2 and rotating the spindle atthe proper speed, the lapping pressure may also be accuratelypredetermined.

A lapping device built in accordance with my invention is rapid inproduction in that the lapping tools may be rotated constantly and thework head withdrawn and new work pieces substituted, all withoutstopping the rotation of the lapping tools and when the work headrotates at a sufficiently slow speed, without stopping its rotation. Itmay be said that, generally speaking, the lapping tools are rotated at arapid rate while the work piece is rotated quite slowly.

It Will be'clear to those skilled in the art that the device may bearranged for lapping the raceway grooves of inner rings of ballbearings.

While the invention has been described in considerable detail and twoforms illustrated, it is to be understood that the invention may bevariously embodied for lapping various articles and surfaces and thatchanges and modiications may be made within the scope of the inventionas dened in the appended claims.

I claim:

1. In a device of the 'character indicated, a support, Ia spindlerotatably mounted thereon, a cylinder xedly mounted on one end of saidspindle, a lapping head xedly mounted on the other end of said spindle,lapping members carried by said head, actuating members for said lappingmembers, a piston in said cylinder, a piston rod passing axially throughsaid spindle and connected to said piston and said actuating members,means for subjecting said piston to uid pressure for actuating saidlapping members, and means for rotating said spindle, cylinder andlapping head as a unit.

2. In .a device of the character indicated, a support, a spindlerotatably mounted thereon, a

lapping head carried by said spindle, lapping' members carried by saidhead, toggle mechanism for actuating said lapping members in at leastone direction, a toggle actuator connected to said toggle mechanism andpassing axially through said spindle, and fluid pressure actuated meansfor moving said toggle actuator for the purpose described.

RAYMQND R. sEARLEs.

